How do I check a second-hand phone is not blocked or stolen?
The four checks worth making before handing over money for a used phone: the IMEI against the blocklist, the account lock, the network lock, and the phone's own state. What each one costs and what it actually proves.
- Difficulty
- beginner
- Time
- 25 min
- Read
- 6 min
- Safety
- caution
Short answer
Dial *#06# on the phone to display its IMEI, then check that number against the industry blocklist before you pay. Separately, watch the phone be reset and reach the home screen with your own account — that is the only proof it is not account-locked. Those two checks together take ten minutes and cover the two ways a used phone becomes worthless.
A second-hand phone can be dead in three different ways, and they are independent. It can be blocked, meaning its IMEI is on the industry's shared database of lost and stolen handsets and no UK network will carry it. It can be account-locked, meaning it is tied to a previous owner's Apple or Google account and cannot be activated at all. It can be network-locked, meaning it works only on one operator, which is the least serious because operators must unlock free of charge on request. All three survive a factory reset and none of them is visible from a photograph, so all three need checking in person, before payment.
Safety
Step by step
- Get the IMEI from the phone itself, in front of you.Dial *#06# and the IMEI appears immediately, without unlocking. It is also in the settings under About, and printed on the SIM tray on some models. Checking a number the seller sent you is worth nothing — sellers of stolen phones send the IMEI of a clean one.
- Check the IMEI against the blocklist.The UK mobile industry maintains a shared database of handsets reported lost or stolen, and a blocked phone loses service on every UK network. Checking services exist, including CheckMEND, which is used by the trade and by police forces; most charge a small fee for a full report and some offer a basic blocklist check free.
- Understand what a clean report does and does not prove.It proves the phone has not been reported yet. A phone stolen this morning is not on the list this afternoon, and an insurance claim made after you buy it can get it blocked weeks later. A report is strong evidence, not a guarantee, which is why paying by a traceable method matters as well.
- Watch it be reset and set up with your account.Ask the seller to factory reset it in front of you, then complete setup with your own Apple or Google account until you reach the home screen. This is the only reliable proof that it is not account-locked, and any seller refusing it is telling you something.
- Check whether it is network-locked.Put your own SIM in and make a call. If it refuses, it is locked to another operator — recoverable, since UK operators must unlock on request and free of charge, and since new phones have not been sold network-locked here since the end of 2021, but it is a delay and a bargaining point.
- Check the physical and battery state while you have it.Battery health figure in settings, every camera lens, the charging port, wireless charging, every button, the speakers and microphone, and whether the screen shows any discolouration. The catalogue's guide on checking a used laptop or phone before buying covers the full list.
- Ask for the original receipt and match the details.A receipt showing the IMEI is the strongest evidence of legitimate ownership there is, and it is also what would let the original buyer get an account lock removed. Its absence is not proof of anything, but its presence is genuinely reassuring.
- Pay by a method with protection.A card, or PayPal goods and services, gives you a route back. Cash and bank transfer give you none, which is exactly why sellers of stolen goods insist on them. For anything over £100 a credit card adds the card provider's joint liability.
Common mistakes
- Checking the IMEI the seller sent you rather than the phone's own — It is trivially easy to send someone else's IMEI. The check is only meaningful when you dial the code on the actual handset yourself.
- Paying in cash to save a fee — The fee buys you the ability to get your money back. On a several-hundred-pound purchase from a stranger, that is the cheapest insurance available.
- Accepting "I'll reset it when I get home" — The reset and setup in front of you is the account-lock check. Deferring it means you find out after paying, when your options have shrunk to a dispute.
If it doesn't work
Seller will not let you dial *#06#
Cause: There is something to hide — Fix: Walk away. There is no legitimate reason to refuse; the code does not unlock anything or reveal anything about the seller.
IMEI on the phone differs from the box or the receipt
Cause: Mismatched paperwork, a replaced part, or a repackaged phone — Fix: The phone's own IMEI is what matters. A mismatch with the box means the paperwork is not for this phone and proves nothing about it.
Phone works, then loses service weeks later
Cause: It was blocked after you bought it — Fix: Contact the seller and the platform immediately, and report it. An insurance claim or a late theft report can trigger this. This is the scenario paying by card protects you against.
Blocklist check comes back with outstanding finance
Cause: The phone is still on a contract or a finance agreement — Fix: It can be blocked if payments stop. This is one of the things a full paid report covers that a free blocklist check does not, and it is a reason to pay for the fuller check on an expensive handset.
Phone will not take your SIM
Cause: Network lock, or a SIM size or eSIM mismatch — Fix: Establish which before assuming the worst. A physical SIM in a phone that only supports eSIM is a compatibility issue, not a lock.
Seller offers a discount for a cash sale with no checks
Cause: Exactly the pattern you are checking for — Fix: The discount is smaller than the loss. Decline.
Questions people ask
What is an IMEI?
A unique 15-digit identifier for the handset itself, separate from the SIM and from your number. It is what networks use to identify a specific device, and it is what the blocklist stores. Dialling *#06# displays it on any phone.
Is a blocklist check free?
Some services offer a basic free check of blocked status. A full report — covering blocked status on each network, previous loss or insurance claims, outstanding finance, and how many owners it has had — is generally paid, at a small fee, and CheckMEND is the best-known UK provider of it. On an expensive phone the fuller report is worth the money.
Does a blocked phone work at all?
It works on wifi as a small tablet, and nothing more — it will not connect to any UK mobile network. Some blocked phones do work abroad, which is why they are exported, and that trade is precisely what the blocklist is designed to disrupt.
What if I have already bought one?
Contact the seller, open a dispute on the platform, and go to your payment provider. Report it to Action Fraud, and to the police if you have reason to think it is stolen. Do not resell it — knowingly passing on a blocked phone is an offence, not a way to recover the money.